An efficient construction of N,N-bicyclic pyrazolidinones comprising enaminonitriles via asymmetric [3+2] cycloaddition

Vishwanath, Manjunatha; Sivamuthuraman, Koilpitchai; Kesavan, Venkitasamy

doi:10.1039/c6cc05304a

Cited by 30 publications

(4 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The use of other dipolarophiles, such as cumulenes, imines, thiones, and nitriles, is another unexplored field of asymmetric cycloadditions of azomethine imines. So far, only reactions with allenoates [ 62 ], ketenes [ 51 ] and nitriles [ 52 ] have been reported.…”

Section: Discussionmentioning

confidence: 99%

“…2-methylmalononitrile also gave the expected product (78% yield, 70% ee ), while other dipolarophiles such as ethyl 2-cyanoacetate, benzoylacetonitrile and (phenylsulfonyl)acetonitrile failed to react. Presumably, the azomethine imine gets activated via hydrogen bonding with the thiourea moiety, whereas the tertiary amine deprotonates/activates the malononitrile ( Scheme 30 ) [ 52 ].…”

Section: Synthesis Of Pyrazolidinesmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of Non-Racemic Pyrazolines and Pyrazolidines by [3+2] Cycloadditions of Azomethine Imines

et al. 2017

View full text Add to dashboard Cite

Asymmetric [3+2] cycloadditions of azomethine imines comprise a useful synthetic tool for the construction of pyrazole derivatives with a variable degree of saturation and up to three stereogenic centers. As analogues of pyrrolidines and imidazolidines that are abundant among natural products, pyrazoline and pyrazolidine derivatives represent attractive synthetic targets due to their extensive applications in the chemical and medicinal industries. Following the increased understanding of the mechanistic aspect of metal-catalyzed and organocatalyzed [3+2] cycloadditions of 1,3-dipoles gained over recent years, significant strides have been taken to design and develop new protocols that proceed efficiently under mild synthetic conditions and duly benefit from superior functional group tolerance and selectivity. In this review, we represent the current state of the art in this field and detailed methods for the synthesis of non-racemic pyrazolines and pyrazolidines via [3+2] metal and organocatalyzed transformations reported since the seminal work of Kobayashi et al. and Fu et al. in 2002 and 2003 up to the end of year 2017.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Synthesis Of Pyrazolidinesmentioning

confidence: 99%

Synthesis of Non-Racemic Pyrazolines and Pyrazolidines by [3+2] Cycloadditions of Azomethine Imines

et al. 2017

View full text Add to dashboard Cite

show abstract

“…These chemical biological activities have also been linked to their ability to scavenge reactive oxygen and nitrogen species, as well as the suppression of neutrophil oxidative burst [31]. Antimicrobial [32,33], antifungal [34], anti-angiogenic [35], antiviral [36], anticancer [37,38], anti-ischemic [39], antiproliferative, antioxidant [40], and cytotoxic [41] actions of these heterocyclic ring systems lead to other applications. In light of these findings, the current research project aims to synthesise chemically a set of new thiophene scaffolds containing the antipyrine moiety and investigate their antioxidant and antibacterial properties.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of some new antipyrine-thiophene hybrids and their evaluations as antioxidant and antibacterial agents

Saleh¹,

Saeed²,

Ghani³

et al. 2022

Bull. Chem. Soc. Eth.

View full text Add to dashboard Cite

ABSTRACT. A novel series of antipyrinyl thienyl ketones 4a-c, 7a-c, 10a-c, and 13a-b was chemically synthesized through the cyclocondensation of 4-chloroacetylantipyrine with various 2-substituted-thioacetanilide scaffolds, including 3-arylazo-4-mercapto-4-phenylamino-buten-2-ones, ethyl 2-arylazo-3-mercapto-3-phenylamino-acrylate, 2-cyano-3-mercapto-3-(phenylamino)-N-arylacrylamide, 4-mercapto-4-(phenylamino)but-3-en-2-one, and/or ethyl-3-mercapto-3-(phenylamino)acrylate. Indeed, the reaction of 4-chloroacetylantipyrine with 4-hydroxybenzaldehyde followed by refluxing with 2-cyanoacetohydrazide yielded 2-cyano-N'-(4-(2-(antipyrin-4-yl)-2-oxoethoxy)benzylidene)-acetohydrazide 17 as a building compound, which was used consequentially to synthesize a set of new antipyrinyl thienyl hybrids 19a-d. The chemical structures of newly synthesised compounds were unambiguously confirmed using extensive elemental and spectral data analyses. The newly synthesized compounds were screened for their antioxidant and antimicrobial activities. Compared to the test reference (Ascorbic acid, 88.0%), the antipyrinyl thienyl ketones 13a and 13b substituted with methyl and/or hydroxyl groups at the thiophene ring system displayed excellent antioxidant properties, 87.8% and 87.2%, respectively. Additionally, antipyrinyl thienyl ketones 13a and 13b showed high antibacterial activities, and their relative activity index (which ranges from 68% to 91.7%) was close to that of a reference compound, Ampicillin. KEY WORDS: 4-Chloroacetylantipyrine, Thioacetanilide, Antipyrinyl thienyl ketones, Antioxidant, Antimicrobial Bull. Chem. Soc. Ethiop. 2023, 37(1), 123-140. a DOI:https://dx.doi.org/10.4314/bcse.v37i1.11

show abstract

“…N , N ′-Cyclic azomethine imines are a class of inexpensive, bench-stable, and readily available building blocks that have been widely used in catalytic asymmetric 1,3-dipolar cycloaddition reactions to synthesize dinitrogen-fused heterocycles . In the realm of NHC catalysis, Scheidt, Chi, and Glorius have done some elegant work using N , N ′-cyclic azomethine imines as suitable reaction partners.…”

mentioning

confidence: 99%

Oxidative Asymmetric [2 + 3] Annulation of Aldehydes with Azomethine Imines Enabled byN-Heterocyclic Carbene Catalysis

et al. 2017

View full text Add to dashboard Cite

An efficient asymmetric [2 + 3] annulation of simple aldehydes with N,N'-cyclic azomethine imines via oxidative N-heterocyclic carbene (NHC) catalysis is disclosed, affording bicyclic pyrazolidinones bearing two vicinal tertiary stereogenic centers with moderate to good yields (56-84% for 19 examples), good to excellent diastereoselectivities (>20:1 for 17 examples), and good to excellent enantioselectivities (66-98% for 19 examples). This direct α-carbon functionalization reaction of aldehyde can be readily performed on gram scale under mild conditions, and a five-membered transition state is proposed to rationalize the stereochemical outcome.

show abstract

An efficient construction of N,N-bicyclic pyrazolidinones comprising enaminonitriles via asymmetric [3+2] cycloaddition

Cited by 30 publications

References 53 publications

Synthesis of Non-Racemic Pyrazolines and Pyrazolidines by [3+2] Cycloadditions of Azomethine Imines

Synthesis of Non-Racemic Pyrazolines and Pyrazolidines by [3+2] Cycloadditions of Azomethine Imines

Synthesis of some new antipyrine-thiophene hybrids and their evaluations as antioxidant and antibacterial agents

Oxidative Asymmetric [2 + 3] Annulation of Aldehydes with Azomethine Imines Enabled byN-Heterocyclic Carbene Catalysis

Contact Info

Product

Resources

About